Sam,
Let me give you my opinion and experience and maybe that might help, as I was where you were several years ago. The trusted dealer recommended here are good to work with - Joshua and Andrew are professional and straight forward, they seem to be the top dealers. I have purchased from both.
I have both Rep Subs and GMTs.
Subs:
I have one 116610 TT Ceramic Sub with a Swiss ETA movement. It is flawless in my opinion and I have compared. It was my first big step and my worries were put to rest. I have another Vintage Sub, it is actually my second as the other just died after several months. Both have/had a Asian 2813 movement. It was inexpensive compared to the TT with the ETA movement. The second one runs like a champ and I have adjusted the timing so it is actually one of my most accurate. I actually ware it the most as it is lighter, inexpensive and if it gets knocked around I don't worry. I am trying to get a replacement movement for the broken one and will give that to a friend. I have another Black Ceramic Sub with an Asian movement however first the pearl fell out and could not get the replacement to stay no matter what glue I used. Then the bezel fell off. Still runs but looking for a case assembly and will swap out the movement and put in the replacement bezel, maybe a blue - just tinkering around.
GMTs:
I have one Coke with a Asian Movement with the separate adjustment for the 24 hour hand. Runs like a champ. I just purchased a new Black and Blue Ceramic GMT Asian Movement. It has some quality issues! Everything is there and the separate pieces are good quality however the alignment of the Dial to the movement/case is miss-aligned. I reviewed the QC pics and discussed with the trusted dealer and was told that it was the camera angle, however when I got the watch he was wrong! Also the Stem got stuck and I was about to throw the watch in the repair pile. Messed with it for awhile and now it is working again. I will wear it to cut the lawn or give it to a friend. On a good note I like the look of the Black and Blue ceramic and am looking to replace it with and Swiss ETA Movement.
I like the Rolex look but I think in the future I will swing toward a Swiss ETA version over the Asian movements. I think the factories pays more attention to there detail so you get a more quality rep. +Cost=+Quality
Read a lot of the posts. Were good people on this forum
A lot of words but hope it helps
Tinker